package com.cxb.utils;

import java.io.File;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.content.Context;
import android.util.Log;

public class FileDownloader {
	/*
	 * down()�ø��߳̽����������
	 */
	private static final String TAG = "FileDownloader";
	private Context context;
	private FileService fileService;

	/* �������ļ����� ---�����߳����ص��ܳ��� */
	private int downloadSize = 0;

	/* ԭʼ�ļ����� */
	private int fileSize = 0;

	/* �߳��� */
	private DownloadThread[] threads;

	/* ���ر����ļ� */
	private File saveFile;

	/* ������߳����صĳ��� */
	private Map<Integer, Integer> data = new ConcurrentHashMap<Integer, Integer>();

	/* ÿ���߳����صĳ��� */
	private int block;

	/* ����·�� */
	private String downloadUrl;

	/**
	 * ��ȡ�߳���
	 */
	public int getThreadSize() {
		return threads.length;
	}

	/**
	 * ��ȡ�ļ���С
	 * 
	 * @return
	 */
	public int getFileSize() {
		return fileSize;
	}

	/**
	 * �ۼ������ش�С
	 * 
	 * @param size
	 */
	protected synchronized void append(int size) {
		downloadSize += size;
	}

	/**
	 * ����ָ���߳�������ص�λ��
	 * 
	 * @param threadId
	 *            �߳�id
	 * @param pos
	 *            ������ص�λ��
	 */
	protected synchronized void update(int threadId, int pos) {
		this.data.put(threadId, pos);
		this.fileService.update(this.downloadUrl, this.data);
	}

	/**
	 * �����ļ�������
	 * 
	 * @param downloadUrl
	 *            ����·��
	 * @param fileSaveDir
	 *            �ļ�����Ŀ¼
	 * @param threadNum
	 *            �����߳���
	 */

	public void setSaveFile(File saveFile) {
		if (saveFile.exists())
			saveFile.delete();
		this.saveFile = saveFile;// ���������ļ�
	}

	public void stopDownload() {
		try {
			if (threads != null) {
				for (DownloadThread thread : this.threads) {
					thread.interrupt();
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public FileDownloader(Context context, String downloadUrl, int threadNum) {
		try {
			this.context = context;
			this.downloadUrl = downloadUrl;
			fileService = new FileService(this.context);
			URL url = new URL(this.downloadUrl);

			this.threads = new DownloadThread[threadNum];

			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			conn.setConnectTimeout(5 * 1000);
			conn.setRequestMethod("GET");
			conn.setRequestProperty("Accept-Language", "zh-CN");
			conn.setRequestProperty("Referer", downloadUrl);
			conn.setRequestProperty("Charset", "UTF-8");
			conn.setRequestProperty(
					"User-Agent",
					"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
			conn.setRequestProperty("Connection", "Keep-Alive");
			conn.connect();
			printResponseHeader(conn);

			if (conn.getResponseCode() == 200) {
				this.fileSize = conn.getContentLength();// �����Ӧ��ȡ�ļ���С
				if (this.fileSize <= 0)
					throw new RuntimeException("Unkown file size ");

				String filename = getFileName(conn);// ��ȡ�ļ����

				Map<Integer, Integer> logdata = fileService
						.getData(downloadUrl);// ��ȡ���ؼ�¼

				if (logdata.size() > 0) {// ���������ؼ�¼
					for (Map.Entry<Integer, Integer> entry : logdata.entrySet())
						data.put(entry.getKey(), entry.getValue());// �Ѹ����߳��Ѿ����ص���ݳ��ȷ���data��
				}

				if (this.data.size() == this.threads.length) {// ������������߳��Ѿ����ص���ݳ���
					for (int i = 0; i < this.threads.length; i++) {
						this.downloadSize += this.data.get(i + 1);
					}

					print("�Ѿ����صĳ���" + this.downloadSize);
				}

				// ����ÿ���߳����ص���ݳ���
				this.block = (this.fileSize % this.threads.length) == 0 ? this.fileSize
						/ this.threads.length
						: this.fileSize / this.threads.length + 1;
			} else {
				throw new RuntimeException("server no response ");
			}
		} catch (Exception e) {
			print(e.toString());
			throw new RuntimeException("don't connection this url");
		}
	}

	/**
	 * ��ȡ�ļ���
	 * 
	 * @param conn
	 * @return
	 */
	private String getFileName(HttpURLConnection conn) {
		String filename = this.downloadUrl.substring(this.downloadUrl
				.lastIndexOf('/') + 1);

		if (filename == null || "".equals(filename.trim())) {// ����ȡ�����ļ����
			for (int i = 0;; i++) {
				String mine = conn.getHeaderField(i);

				if (mine == null)
					break;

				if ("content-disposition".equals(conn.getHeaderFieldKey(i)
						.toLowerCase())) {
					Matcher m = Pattern.compile(".*filename=(.*)").matcher(
							mine.toLowerCase());
					if (m.find())
						return m.group(1);
				}
			}

			filename = UUID.randomUUID() + ".tmp";// Ĭ��ȡһ���ļ���
		}

		return filename;
	}

	/**
	 * ��ʼ�����ļ�
	 * 
	 * @param listener
	 *            �������������ı仯,�����Ҫ�˽�ʵʱ���ص�����,��������Ϊnull
	 * @return �������ļ���С
	 * @throws Exception
	 */
	public int download(DownloadProgressListener listener) throws Exception {
		try {
			RandomAccessFile randOut = new RandomAccessFile(this.saveFile,
					"rwd");
			if (this.fileSize > 0)
				randOut.setLength(this.fileSize);
			randOut.close();
			URL url = new URL(this.downloadUrl);

			if (this.data.size() != this.threads.length) {
				this.data.clear();

				for (int i = 0; i < this.threads.length; i++) {
					this.data.put(i + 1, 0);// ��ʼ��ÿ���߳��Ѿ����ص���ݳ���Ϊ0
				}
			}

			for (int i = 0; i < this.threads.length; i++) {// �����߳̽�������
				int downLength = this.data.get(i + 1);
				// �����߳�һ���������ˣ��Ͳ��ÿ����߳�
				if (downLength < this.block
						&& this.downloadSize < this.fileSize) {// �ж��߳��Ƿ��Ѿ��������,�����������
					this.threads[i] = new DownloadThread(this, url,
							this.saveFile, this.block, this.data.get(i + 1),
							i + 1);
					this.threads[i].setPriority(7);
					this.threads[i].start();
				} else {
					this.threads[i] = null;
				}
			}

			this.fileService.save(this.downloadUrl, this.data);
			boolean notFinish = true;// ����δ���

			while (notFinish) {// ѭ���ж������߳��Ƿ��������
				Thread.sleep(900);
				notFinish = false;// �ٶ�ȫ���߳��������

				for (int i = 0; i < this.threads.length; i++) {
					if (this.threads[i] != null && !this.threads[i].isFinish()) {// ������߳�δ�������
						notFinish = true;// ���ñ�־Ϊ����û�����

						if (this.threads[i].getDownLength() == -1) {// �������ʧ��,����������
							this.threads[i] = new DownloadThread(this, url,
									this.saveFile, this.block,
									this.data.get(i + 1), i + 1);
							this.threads[i].setPriority(7);// �����̵߳����ȼ�
							this.threads[i].start();
						}
					}
				}

				if (listener != null)
					listener.onDownloadSize(this.downloadSize);// ֪ͨĿǰ�Ѿ�������ɵ���ݳ���
			}

			fileService.delete(this.downloadUrl);
		} catch (Exception e) {
			print(e.toString());
			throw new Exception("file download fail");
		}
		return this.downloadSize;
	}

	public void clearAllTaskCache() {
		if (fileService != null) {
			fileService.deleteALL();
		}
	}

	/**
	 * ��ȡHttp��Ӧͷ�ֶ�
	 * 
	 * @param http
	 * @return
	 */
	public static Map<String, String> getHttpResponseHeader(
			HttpURLConnection http) {
		Map<String, String> header = new LinkedHashMap<String, String>();

		for (int i = 0;; i++) {
			String mine = http.getHeaderField(i);
			if (mine == null)
				break;
			header.put(http.getHeaderFieldKey(i), mine);
		}

		return header;
	}

	/**
	 * ��ӡHttpͷ�ֶ�
	 * 
	 * @param http
	 */
	public static void printResponseHeader(HttpURLConnection http) {
		Map<String, String> header = getHttpResponseHeader(http);

		for (Map.Entry<String, String> entry : header.entrySet()) {
			String key = entry.getKey() != null ? entry.getKey() + ":" : "";
			print(key + entry.getValue());
		}
	}

	/**
	 * ��ӡ��־��Ϣ
	 * 
	 * @param msg
	 */
	private static void print(String msg) {
		Debug.printf(TAG, msg);
	}
}
